1. Field of the Invention
This invention relates to a method and apparatus for binding sheets of paper inside a cover and more particularly to a permanent binding which utilizes pre-punched holes in the paper sheets.
2. Description of the Prior Art
Sheets of paper containing punched or drilled holes frequently are employed where it is desirable to bind and unbind a book as in ring looseleaf or post binders.
However, several binding methods employ sheets containing holes where unbinding is not contemplated. Examples are plastic loops and/or spiral wire. Uses for such permanent bindings include sales literature, typed or written reports, legal briefs, etc. as employed in schools, business, and industry.
A disadvantage with prior, permanent binding methods is the necessity of introducing mounting holes into the cover and the paper sheets. Also, binding methods such as spiral wire or plastic loops must be carefully threaded through the cover and paper sheets, resulting in slow production time and expensive machinery.
If the permanent binding mechanism utilizes protrusion through all the holes in a standard five hole paper sheet, then the binding is not compatible with a standard three hole sheet since two of the protrusions would not pass through the papers.